#2**+5 **

how do i solve 2^x=7?

Let me give you an example.....then you should be able to do this one....

Suppose we had 4^{x} = 9

First....take the "log" of both sides......this gives us

log 4^{x} = log 9

By a property of logarithms, we can bring the "x" in front of the "log 4"......and we have

x log 4 = log 9......now, divide both sides by the "log 4" .....and we have

x = log 9 / log 4........ we can evaluate this on the calculator on this site, and we find that

x ≈ 1.58

* Be careful !!! Some students - mistakenly - take the log of (9/4).....this is NOT* the same thing as

log 9 / log 4

I think you have enough to get you on the right road, now.........

CPhill Apr 19, 2014

#2**+5 **

Best Answer

how do i solve 2^x=7?

Let me give you an example.....then you should be able to do this one....

Suppose we had 4^{x} = 9

First....take the "log" of both sides......this gives us

log 4^{x} = log 9

By a property of logarithms, we can bring the "x" in front of the "log 4"......and we have

x log 4 = log 9......now, divide both sides by the "log 4" .....and we have

x = log 9 / log 4........ we can evaluate this on the calculator on this site, and we find that

x ≈ 1.58

* Be careful !!! Some students - mistakenly - take the log of (9/4).....this is NOT* the same thing as

log 9 / log 4

I think you have enough to get you on the right road, now.........

CPhill Apr 19, 2014